Seven Eleven
Given a seven-digit number,whose digits add up to 59.Find the probability that the number is divisible by 11.
PS: Would this qualify as a puzzle?? And sorry for any bitter exam-related memories I may have inadvertently invoked in some of you...:)
~sai
PS: Would this qualify as a puzzle?? And sorry for any bitter exam-related memories I may have inadvertently invoked in some of you...:)
~sai
posted by littlecow at 4/02/2006 12:17:00 PM
10 Comments:
@sai: welcome to xyfactor!
is it 60/154? nailed down 154 possibilities and shamefully brute forced through them all.
@grenade: i could have made a mistake in counting the total number of cases... the partitions of 59 that would work are 5+9+9+9+9+9+9, 6+8+9+9+9+9+9, 7+8+8+9+9+9+9 resulting in 7+42+105 cases...i think?
Bullseye! Grenade has the right answer: 4/21 or 40/210.
>littlecow: Thank you! I have always enjoyed visiting xyfactor.....
Too bad you miscalculated the total number of possibilities(phew)...better luck next time!
Grrr... :)
@grenade: one question, you directly multiplied 4 and 10 to get 40, but does that count all solutions ? i.e. let's take a 5 digit number with the odd digit values 3,4 and 4, and even digit values 1 and 2. The even digits can be arranged in 2 ways and the odd digits can be arranged in 3 ways, so according to you calculation, it will give 2x3=6 ways, but the numbers 1,2,3,4,4 can be arranged in 5!/2! ways to produce 60 distinct numbers. what am i missing ?
b.t.w., folks, sai is my puzzle-loving cousin.
@grenade: clear, thanks for elucidating.
This is very interesting site... bishop car insurance Zithromax suspension California low cost auto insurance License plate frames hawaii Usaa auto insurance frankfurt germany office Wendy whopper gangbang Mega millions result virginia site en.wikipedia.org Tooth whitener angeles Girl pees bed tamiflu gegen vogelgrippe venlafaxine and bipolar disorder sleeper sofa arts and crafts auto insurance Dale jr. sofa Cheep air tokyo fare Boise idaho wheelchair minivan Mexico pain relief cheap
Keep up the good work Blackberry danger
Enjoyed a lot! Dell computer marketing strategy Inflatable woman sex toy refrigerators ge
Post a Comment
<< Home